Human ingest a wide variety of nonpolar or fat soluble substances. While many of these substances are necessary micronutrients or drugs, others are toxic and/or carcinogenic. Common examples are fossil fuel hydrocarbons, vitamins A, D, E and K, many drugs and food additives, the essential oils of plants and a myriad of industrial pollutants and biological control agents (e.g., pesticides and herbicides). These has never been a satisfactory explanation of how such hydrophobic chemicals (aqueous solubilities of 10 to the minus 10th power - 10 to the minus 14th M power) could be dispersed during digestion and because of this it has generally been assumed that they are poorly absorbed. We have discovered how high concentrations of nonpolar molecules are dispersed during fat digestion. Fluorescent nonpolar molecules were dissolved in triglyceride (fat droplets) and the enzymatic digestion of the droplets was followed by fluorescence microscopy. The fluorescent triglyceride was converted directly into fluorescent product phases. These observations indicate that there is a continuous hydrocarbon domain in triglyceride which remains intact during the enzymatic conversion of the triglyceride to fatty acid and monoglyceride. The preservation of this hydrocarbon domain during fat digestion allows non-polar molecules that are dissolved within it to flow from non-dispersable triglyceride to the products of fat digestion which are dispersed by bile salts and absorbed. The concept of an uninterrupted hydrocarbon domain during fat digestion that can carry many different molecules has profound significance for human health and disease; it explains how a large family of biologically important molecules are dispersed in the intestine and thereby absorbed; it offfers a mechanism to explain food chain magnification of hydrophilic pollutants and toxins, it is the logical pathway of intestinal entry of nonpolar carcinogens and it reveals a rapid and simple method of drug delivery. The objective of the proposed research is to determine (for representative compounds) the carrying capacity of the hydrocarbon domain in intact triglyceride, in the product phases and in the micellar phase. Experiments will be designed to show the effects of nonpolar molecular structure, triglyceride structure, enzyme and bile salt concentration and physical-chemical conditions on the dispersion of nonpolar molecules during fat digestion.